A class for finite and recursively enumerable types and some helper functions for enumerating them defined in universe-base package:

class Universe a where universe :: [a]
class Universe a => Finite a where universeF :: [a]; universeF = universe

This package adds

class UniverseSome f where universeSome :: [Some f]
class UniverseSome f => FiniteSome f where universeFSome :: [Some f]; universeFSome = universe

classes.